Reference
Gold Purity Guide
Pure gold is too soft for jewelry, so it is alloyed with copper, silver or palladium. The karat (k) tells you how much pure gold the alloy contains — out of 24 parts.
| Karat | Fineness stamp | Pure gold | Common use |
|---|---|---|---|
| 24k | 999 | 99.9% | Bullion bars and coins. Too soft for everyday jewelry. |
| 22k | 916 | 91.7% | Premium jewelry — standard in India, Middle East, South-East Asia. |
| 21k | 875 | 87.5% | Common in Gulf states and Egypt. |
| 18k | 750 | 75.0% | High-end Western jewelry. Good balance of color and durability. |
| 14k | 585 | 58.5% | Most common Western jewelry — durable and affordable. |
| 10k | 417 | 41.7% | Budget jewelry. Legal minimum to be sold as 'gold' in the US. |
Reading hallmark stamps
Most gold jewelry carries a tiny stamp on the inside of a ring, the clasp of a chain, or the back of a pendant. You will see either the karat number (e.g. "18K", "750") or the fineness as parts per thousand (e.g. "0.750", "750"). UK pieces also carry an assay-office mark and a date letter.